Ecology - Antarctica Adaptations Flashcards
What do species adapt to?
High O2 concentrations and cold tempereratures.
Most prominent southern ocean fish….
Notothenioidei
Features of Notothenioidei,
Complete loss of NADH-6-dehydrogenase
Antifreeze Glycoproteins
Reduced HG
Antifreeze Glycoproteins
Allow avoidance of freezing by binding H20 and preventing ice crystal formation.
Structure of antifreeze glycopreoitnes.
Monomeric repeats of Thr-Ala-Ala each Thr linked to the A disaccharide galactose-N-acetyl galactosamine
Why do Channichthyidae lack hemoglobin?
Hihg O2 in southern ocean allows direct despotion through soltions.
Ambient air tempreatures of the southern ocean?
-40 to -60 whilst oceans near freezing
Mechanisms of controlling heat loss…
Conduction/Convection
Radiation/Evaporation
Behavioural adaptations…
Reducing surface area by curling or huddling in pengions
Examples of integumentary adaptaitons…
Winter plumage and blubber insulate
Fur insultaion…
Piloerection increases, however efficiency low in sleet, winds and water.
How is conductive heat loss maintained?
Peripiheral tissue cooling whilst maintaining core temperatre
Counter-current heat exchange
Prevents excessive heat loss being a two-phase flow regime which the working fluids flow in opposite directions.
Structure of Counter-current heat exchange mech…
Veins and Arteris run in close contact, two concentric conduits warm arterial blood cooled by the venus blood.
Risk of physical activity…
Overheating
Physical activity overheating adaptations…
Selective brain cooling
Icewater
Thermoregulation importance in young….
Smaller size and wetness at birth.
Altricial
Young hatched and requiring significant parental care
Precocials
Born in advanced states able to feed themselves and move independetly.
Thermogenesis
The dissipation of energy through the production of heat.
Adaptations to food availability…
Lower basal metabolic rate
Physical activity lower
Fat storage
Hibernation
Surpus killing
Photoperiod at the poles…
Days can change up to 30 min a day…
Mechanism of circadian rhytmh….
Pineal gland recives information when stimulated by visual recogniton of light ocnditiosn.
Function of melatonin…
Synchronizes the circadian rhytmhs…
How do full-light animals recognise feeding times?
Recognise spectral compostion changes.